When fixing or upgrading computers, I am usually able to get the job done in a reasonable amount of time.

If I have to purchase parts, I will always enclose the original receipt so you know I am charging you properly, and in case there are problems later on.

I charge a bench fee of $25 (That is, $25 to look at the computer).
I charge $20 per hour for repairing your computer.
I also add whatever cost accumulates due to the purchase of parts.

I will call around to try to get the cheapest prices on the highest quality parts I can find.